add lit based tests

Author: vchuravy

test/codegen/PTX/atomics-i128.ll

@@ -1,4 +1,7 @@
-define void @test(ptr %a) nounwind {git
+; RUN: gpuc %s 2>&1 | FileCheck %s
+
+; CHECK: ERROR: LoadError: LLVM error: Undefined external symbol "__sync_val_compare_and_swap_16"
+define void @test(ptr %a) nounwind {
   %1 = load atomic i128, ptr %a seq_cst, align 16
   store atomic i128 %1, ptr %a seq_cst, align 16
   ret void

test/codegen/gpuc.jl

@@ -1,12 +1,13 @@
 using GPUCompiler
 import LLVM
+using Test # for helpers/precompile.jl
 
 if !GPUCompiler.__llvm_initialized[]
-    InitializeAllTargets()
-    InitializeAllTargetInfos()
-    InitializeAllAsmPrinters()
-    InitializeAllAsmParsers()
-    InitializeAllTargetMCs()
+    LLVM.InitializeAllTargets()
+    LLVM.InitializeAllTargetInfos()
+    LLVM.InitializeAllAsmPrinters()
+    LLVM.InitializeAllAsmParsers()
+    LLVM.InitializeAllTargetMCs()
     GPUCompiler.__llvm_initialized[] = true
 end
 
@@ -22,7 +23,7 @@ end
 job, _ = PTX.create_job(identity, (Int,))
 
 asm, meta = JuliaContext(opaque_pointers=true) do ctx
-    ir = parse(LLVM.Module, readfile(ARGS[end]))
+    ir = parse(LLVM.Module, read(ARGS[end], String))
     GPUCompiler.emit_asm(job, ir, LLVM.API.LLVMAssemblyFile)
 end
 

test/runtests.jl

@@ -56,6 +56,7 @@ for (rootpath, dirs, files) in walkdir(@__DIR__)
   end
   isempty(files) && continue
   basename(rootpath) == "helpers" && continue
+  basename(rootpath) == "codegen" && continue
 
   # strip extension
   files = map(files) do file